VERITAS Volume Manager 4.1 Migration Guide HP-UX 11i v2 Fifth Edition Manufacturing Part Number: 5991-1841 September 2005 Printed in the United States © Copyright 2005 VERITAS Software Corporation.
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Contents About This Document 1. VxVM and LVM Summary . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Introducing the VERITAS Volume Manager . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Notable Features of VxVM . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . VERITAS Volume Manager includes the following features:. . . . . . . . . . . . . . . . . . . .
Contents 3. Command Differences LVM and VxVM Command Equivalents. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Comparison of LVM and VxVM Tasks . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Tasks With No Direct LVM Equivalents. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Existing Features in LVM not supported in VxVM . . . . . . . . . . . . . . . . . . . . . . . . . . . . 50 57 67 69 4.
About This Document This Guide describes how to migrate from HP-UX Logical Volume Manager (LVM) to VERITAS Volume Manager (VxVM,) and convert disks and volumes managed by LVM to VxVM. It includes information on differences between VxVM and LVM commands and terminology. This Guide also discusses the use of both graphical user interfaces: VERITAS Enterprise Administrator (VEA), the Volume Manager GUI, and SAM (System Administration Manager), the Logical Volume Manager GUI.
Table 1 Document Organization (Continued) Chapter 6 Description Chapter 3, Command Differences, Describes the differences between LVM and VxVM commands. It also lists LVM tasks and equivalent or similar VxVM tasks. Chapter 4, SAM and the VEA, Describes the usage of VERITAS Volume Manager's GUI (VEA) and its relationship with HP-UX SAM (System Administration Manager).
Publication History The manual publication date and part number indicate its current edition. The publication date will change when a new edition is released. The manual part number will change when extensive changes are made. To ensure that you receive the new editions, you should subscribe to the appropriate product support service. See your HP sales representative for details. • First Edition: December 2002, 5187-1878, HP-UX 11i Version 1(B.11.
• VERITAS Storage Foundation 4.
Typographic Conventions Table 2 describes the typographic conventions used in this document. Table 2 Typographic Conventions Typeface Usage Examples Computer output, files, directories, software elements such as command options, function names, and parameters Read tunables from the /etc/vx/tunefstab file. italic New terms, book titles, emphasis, variables replaced with a name or value See the VERITAS Volume Manager 4.1 Migration Guide for details.
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1 VxVM and LVM Summary This chapter provides an overview of the VERITAS Volume Manager (also referred to as VxVM) and its features. A brief description of the benefits of migrating from the HP-UX Logical Volume Manager (LVM) to VxVM, and the coexistence of VxVM disks with LVM disks is also given.
VxVM and LVM Introducing the VERITAS Volume Manager • The VERITAS Volume Manager is integrated with HP MC/ServiceGuard and ServiceGuard OPS Edition for High Availability, but requires a specific version of the ServiceGuard products. Refer to the VERITAS Volume Manager Release Notes for details about the required version number, as well as the availability of specific features in your release.
VxVM and LVM Introducing the VERITAS Volume Manager DMP support may be used with devices that show improved performance when I/O is balanced across the multiple paths such as xp256, EMC Symmetrix disk array, and other OEM array devices. • Multiple mirroring with up to 32 mirror copies of a volume's address space.
VxVM and LVM VxVM and LVM-Conceptual Comparison VxVM and LVM-Conceptual Comparison The following section compares the terminology used in LVM and VxVM at a conceptual level. For more information, refer to the glossary of this Guide for precise and detailed definitions of these terms. Table 1-1 A Conceptual comparison of LVM and VxVM LVM Term VxVM Term LVM VxVM Both LVM and VxVM enable online disk storage management. They both build virtual devices, called volumes, on physical disks.
VxVM and LVM VxVM and LVM-Conceptual Comparison Table 1-1 A Conceptual comparison of LVM and VxVM (Continued) LVM Term VxVM Term LVM VxVM An LVM logical volume and a VxVM volume are conceptually the same. Both are virtual disk devices that appear to applications, databases, and file systems like physical disk devices, but do not have the physical limitations of physical disk devices. Due to its virtual nature, a volume (LVM or VxVM) is not restricted to a particular disk or a specific area of a disk.
VxVM and LVM VxVM and LVM-Conceptual Comparison Table 1-1 A Conceptual comparison of LVM and VxVM (Continued) LVM Term VxVM Term LVM VxVM User data is contained in physical extents in LVM and subdisks in VxVM. The LVM physical extents are of a fixed length. LVM allocates space in terms of physical extents which is a set of physical disk blocks on a physical volume. The extent size for all physical volumes within a volume group must be the same, and is usually 4 MB.
VxVM and LVM Coexistence of VxVM and LVM Disks Table 1-1 A Conceptual comparison of LVM and VxVM (Continued) LVM Term VxVM Term LVM Export VxVM Deport In LVM, exporting removes volume group information from /etc/lvmtab. The volume group must have already been deactivated. Similarly in VxVM, deport makes a disk group inaccessible by the system. Import Import In LVM, import adds a volume group to the system and the volume group information to /etc/lvmtab but does not make the volumes accessible.
VxVM and LVM Coexistence of VxVM and LVM Disks Both LVM and VxVM utilities are aware of the other volume manager, and will not overwrite disks that are being managed by the other volume manager. The administrative utilities (SAM and vmsa) recognize and identify all disks on the system (see Chapter 4, “SAM and the VEA,” on page 71, for details). The vxvmconvert command is provided to enable LVM disks to be converted to a VxVM disk format without losing any data.
2 Converting LVM to VxVM Summary This chapter explains how to convert your LVM configuration to a VxVM configuration and presents the following main topics: • “Converting Unused LVM Physical Volumes to VxVM Disks” on page 3 • “Converting LVM Volume Groups to VxVM Disk Groups” on page 5 • “Restoring the LVM Volume Group Configuration” on page 16 • “Examples” on page 20 The basic tools for conversion are the VxVM commands, vxvmconvert and vxdiskadm, and the LVM administrative utilities such as pvremo
Converting LVM to VxVM Converting Unused LVM Physical Volumes to VxVM Disks CAUTION Exercise caution while using this procedure to give disks over to VxVM. You must be absolutely certain that the disks are not in use in any LVM configuration. If there is any user data on these disks, it will be lost during conversion.
Converting LVM to VxVM Converting LVM Volume Groups to VxVM Disk Groups Converting LVM Volume Groups to VxVM Disk Groups This section outlines the process for converting LVM volume groups to VxVM disk groups. NOTE It is recommended that you read through this section carefully before beginning any volume group conversion. The conversion process involves many steps. Though there are tools to help you with the conversion, some of these steps cannot be automated.
Converting LVM to VxVM Converting LVM Volume Groups to VxVM Disk Groups In the conversion of LVM to VxVM, the areas of the disks used to store LVM metadata are overwritten with VxVM metadata. If the VxVM metadata that needs to be written will not fit the space occupied by the LVM metadata, the group containing the disk cannot be converted. If you have just enough space for the conversion, you probably would want to have more space for future configuration changes.
Converting LVM to VxVM Converting LVM Volume Groups to VxVM Disk Groups vxvmconvert will not convert any volume group with dump or primary swap volumes. These are volumes known to the boot process. However, swap volumes on volumes other than the root volume can be converted (as long as this volume is not in the same volume group as the root volume). • Volume group disks used in MC/ServiceGuard clusters.
Converting LVM to VxVM Converting LVM Volume Groups to VxVM Disk Groups Conversion Process Summary Several steps are used to convert LVM volume groups to VxVM disk groups. Most of these steps can be done with the vxvmconvert utility. All the steps are not compulsory, and some may have to be followed only if there are problems during conversion. Some of them (for example, backing up user data) are left to you to accomplish through your regular administrative processes.
Converting LVM to VxVM Converting LVM Volume Groups to VxVM Disk Groups You can also list the LVM disks with the following VxVM command: # vxdisk list 2. Analyzing an LVM volume group to see if conversion is possible After you have selected a volume group for conversion, you need to analyze it to determine if conversion for VxVM use is possible. Use the analyze option of vxvmconvert to check for problems that would prevent the conversion from completing successfully.
Converting LVM to VxVM Converting LVM Volume Groups to VxVM Disk Groups After analysis you know which volume group or groups you want to convert to VxVM disk groups. Up to this point, you have not altered your LVM configuration. By taking the next step (completing the conversion to VxVM), you are significantly changing access to your storage. Although the conversion process does not move, or in any other way affect user data, you are strongly encouraged to back up all data on the affected disks.
Converting LVM to VxVM Converting LVM Volume Groups to VxVM Disk Groups CAUTION Before you do the backup, you should carefully review “9. Implementing changes for new VxVM logical volume names” on page 14. Backup processes and systems themselves may have dependencies on the volume names currently in use on your system. The conversion to VxVM changes those names. You are advised to understand the implications name changes have for restoring from the backups you are about to make.
Converting LVM to VxVM Converting LVM Volume Groups to VxVM Disk Groups • Scripts run by cron (1M). • Other administrative scripts. A Workaround vxvmconvert records a mapping between the names of the LVM device nodes and VxVM device nodes. This data can be used to create symbolic links from the old LVM volume to the new VxVM device names. The mapping is recorded in the file: /etc/vx/reconfig.d/vgrecords/vol_grp_name/vol_grp_name.
Converting LVM to VxVM Converting LVM Volume Groups to VxVM Disk Groups As described in "Conversion and Reboot", vxvmconvert tries to unmount mounted file systems during the conversion. Bear in mind though, that vxvmconvert makes no attempt to close down running applications on those file systems, nor does it attempt to deal with applications (e.g., databases) running on raw LVM volumes. NOTE It is strongly recommended that you do not rely on vxvmconvert's mechanisms for unmounting file systems.
Converting LVM to VxVM Converting LVM Volume Groups to VxVM Disk Groups vxvmconvert will prompt for a name for the VxVM disk group that will be created to replace the LVM volume group you are converting. This is the only object naming that is done through vxvmconvert. For details on modifying VxVM volume names, see “11. Tailoring your VxVM configuration” on page 14 as described earlier in “2.
Converting LVM to VxVM Restoring the LVM Volume Group Configuration The disks in the new VxVM disk group are given VxVM disk media names (see vxintro (1M)) based on this disk group name. If your new VxVM disk group is dg08, it will have VxVM disks with names like dg0801, dg0802, etc. The VxVM plexes within the logical volumes will be dg0801-01, dg0801-02, etc. If you do not like the default object names generated by the conversion, use the standard VxVM utilities to rename these objects.
Converting LVM to VxVM Restoring the LVM Volume Group Configuration • rollback using vxvmconvert Use rollback only if the VxVM configuration has not changed since the conversion. This method restores the LVM configuration without the need for user data restoration. See “Rollback to LVM Using vxvmconvert” on page 17 for details on using this method.
Converting LVM to VxVM Restoring the LVM Volume Group Configuration Rollback to LVM Using vxvmconvert Rollback replaces the VxVM disk groups with the original LVM volume groups. During conversion, vxvmconvert saves a "snapshot" of the original LVM metadata and associated configuration files, such as /etc/fstab and LVM device files. It restores only the LVM metadata and configuration files from this snapshot; user data is not changed.
Converting LVM to VxVM Restoring the LVM Volume Group Configuration Full LVM Restoration If you need to restore the original LVM configuration, but changes have been made to the VxVM configuration, you cannot use the rollback option of vxvmconvert. In this case, you must restore the user data in addition to restoring the old LVM metadata and associated configuration files. You may need to use this method if the disks in use by the LVM/VxVM volumes were corrupted during or after conversion.
Converting LVM to VxVM Examples Examples Example: displaying the vxvmconvert menu To display the vxvmconvert menu, use the following command: # vxvmconvert The following menu is displayed: Volume Manager Support Operations Menu: Volume Manager/LVM_Conversion 1 Analyze LVM Volume Groups for Conversion 2 Convert LVM Volume Groups to VxVM 3 Roll back from VxVM to LVM list List disk information listvg List LVM Volume Group information ? Display help about menu ?? Display help about the menuing syst
Converting LVM to VxVM Examples c0t9d0 - - LVM c0t10d0 disk01 rootdg online c0t11d0 - - online Device to list in detail [
,none,q,?] (default: none) none Example: listing LVM volume group information To list LVM volume group information, use the listvg option of vxvmconvert. Select the listvg option from the vxvmconvert Main Menu: Menu: Volume Manager/LVM_Conversion/ListLVMVolumeGroups # listvg Use this menu option to display a list of LVM volume groups.Converting LVM to VxVM Examples --- Volume groups --VG Name /dev/vg08 VG Write Access read/write VG Status available Max LV 255 Cur LV 2 Open LV 2 Max PV 16 Cur PV 1 Act PV 1 Max PE per PV 1016 VGDA 2 PE Size (Mbytes) 4 Total PE 250 Alloc PE 250 Free PE 0 Total PVG 0 --- Logical volumes --LV Name /dev/vg08/lvol1 LV Status available/syncd LV Size (Mbytes) 500 Allocated PE 125 Used PV 1 --- Physical Extent --LV Name /dev/vg08/lvol2 LV Status available/syncd LV Si
Converting LVM to VxVM Examples Current LE 125 Allocated PE 125 Used PV 1 --- Physical volumes --PV Name /dev/dsk/c0t8d0 PV Status available Total PE 250 Free PE 0 List another LVM Volume Group? [y,n,q,?] (default: n) Select an operation to perform: NOTE The volume groups you want to convert must not be a root volume group or have bootable volumes in the group.
Converting LVM to VxVM Examples Select an operation to perform: 1 Analyze one or more LVM Volume Groups Menu: Volume Manager/LVM_Conversion/Analyze_LVM_VGs Use this operation to analyze one or more LVM volume groups for possible conversion using the VxVM Volume Manager. This operation checks for problems that would prevent the conversion from completing successfully.
Converting LVM to VxVM Examples and the disk device c4t8d0 will be added to the disk group with the disk name dg0801. The c4t8d0 disk has been configured for conversion. The first stage of the Analysis process has completed successfully. Second Stage Conversion Analysis of vg08 Analysis of vg08 found sufficient Private Space for conversion Conversion Analysis of c4t8d0 indicates that the Volume Group is still in use, which may prevent the completion of the conversion without having to reboot the system.
Converting LVM to VxVM Examples Menu: Volume Manager/LVM_Conversion/Analyze_LVM_VGs Use this operation to analyze one or more LVM volume groups for possible conversion using the VxVM Volume Manager. This operation checks for problems that would prevent the conversion from completing successfully. It calculates the space required to add the volume groups disks to a Volume Manager disk group, and to replace any existing partitions and volumes with Volume Manager volumes, plexes, and sub-disks.
Converting LVM to VxVM Examples Analysis of vg08 found insufficient Private Space for conversion SMALLEST VGRA space= 176 RESERVED space sectors = 78 PRIVATE SPACE/FREE sectors = 98 AVAILABLE sector space = 49 AVAILABLE sector bytes = 50176 RECORDS neededs to convert = MAXIMUM records allowable= 399 392 The smallest disk in the Volume Group (vg08) does not have sufficient private space for the conversion to succeed.
Converting LVM to VxVM Examples 2 Convert LVM Volume Groups to VxVM 3 Roll back from VxVM to LVM list List disk information listvgList LVM Volume Group information ? Display help about menu ?? Display help about the menuing system q Exit from menus Select an operation to perform: 2 Convert one or more LVM Volume Groups Menu: VolumeManager/LVM_Conversion/Convert_LVM_VGs Use this operation to convert one or more LVM Volume Groups to one or more VxVM disk groups.
Converting LVM to VxVM Examples vg00 ROOT c4t6d0 vg05 Non-Root c4t5d0 vg03 Non-Root c4t3d0 c4t2d0 vg08 Non-Root c4t8d0 Select Volume Groups to convert : [,all,list,listvg,q,?] vg08 vg08 Convert this Volume Group? [y,n,q,?] (default: y) Name a new disk group [,list,q,?] (default: dg08) The following disk has been found in the vg08 volume group and will be configured for conversion to a VxVM disk group.
Converting LVM to VxVM Examples device. You will need to update any other references such as backup scripts, databases,or manually created swap devices. If you do not like the default names chosen for the corresponding logical volumes, you may change these to whatever you like using vxedit.
Converting LVM to VxVM Examples The Volume Manager is now reconfiguring (partition phase)... Volume Manager: Initializing c4t8d0 as a converted LVM disk. The system reconfiguration will now be done without rebooting. The Volume Manager is now reconfiguring (initialization phase)... Volume Manager: Adding dg0801 (c4t8d0) as a converted LVM disk. Adding volumes for c4t8d0... Starting new volumes... Updating /etc/fstab... The system will now Convert the LVM Volume Groups over to VxVM disk groups.
Converting LVM to VxVM Examples Use this operation to convert one or more LVM Volume Groups to one or more VxVM disk groups. This adds the disks to a disk group and replaces existing partitions with volumes. LVM-VxVM Volume Group conversion may require a reboot for the changes to take effect. For this release, only Non-root LVM Volume Groups are allowed to be converted. More than one Volume Group or pattern may be entered at the prompt.
Converting LVM to VxVM Examples c4t8d0 A new disk group dg08 will be created and the disk device c4t8d0 will be converted and added to the disk group with the disk name dg0801. The c4t8d0 disk has been configured for conversion. The first stage of the conversion operation has completed successfully.
Converting LVM to VxVM Examples RECORDS neededs to convert= 399 MAXIMUM records allowable = 392 The smallest disk in the Volume Group (vg08) does not have sufficient private space for the conversion to succeed. There is only enough private space for 392 VM Database records and the conversion of Volume Group (vg08) would require enough space to allow 399 VxVM Database records. This would roughly translate to needing an additional 896 bytes available in the private space.
Converting LVM to VxVM Examples c0t8d0 - - LVM c0t9d0 - - LVM c0t10d0 disk01 rootdg online c0t11d0 - - online Disk group: rootdg What does vxmvconvert list display? The device indicates a physical disk, a disk with a name indicates if the disk is under VxVM control, a group shows the disk group name, and the status indicates if it is an LVM disk. If the status is online, that means VxVM acknowledges the disk but doesn't have it under its control.
Converting LVM to VxVM Examples c0t8d0 dg0801 dg08 online c0t9d0 - LVM c0t10d0 disk01 rootdg online c0t11d0 - - online Disk group: rootdg Example of the vxprint output after conversion: TY NAME ASSOC KSTATE LENGTH PLOFFS STATE TUTILO PUTIL0 dg dg08 dg08 - - - - - - dm dg0801 c0t8d0 - 2080768 - - - - v dg08lv1 fsgen ENABLED 102400 - ACTIVE - - pl dg08lv1-01 dg08lv1 ENABLED 102400 - ACTIVE - - sd dg0801-01 dg08lv1-01 ENABLED 102400 0 - - - - vxprint Explaine
Converting LVM to VxVM Examples list List disk information listvgList LVM Volume Group information ? Display help about menu ?? Display help about the menuing system q Exit from menus Select an operation to perform: 3 Rollback one or more LVM Volume Groups Menu: VolumeManager/LVM_Conversion/Rollback_LVM_VG Use this operation to rollback from a conversion of an LVM Volume Group. This operation will tear down the VxVM disk group and recreate the LVM volume group in its original form.
Converting LVM to VxVM General Information Regarding Conversion Speed General Information Regarding Conversion Speed The speed of the process of converting an existing LVM volume group to a similar VxVM disk group is largely dependent upon the size of the volume group being converted, as well as on the complexity of the volumes within that volume group. Factors affecting conversion speed include: • Size of volume groups. The larger the volume groups, the larger the LVM metadata on each disk.
Converting LVM to VxVM General Information Regarding Conversion Speed NOTE 36 If you convert mirrored volumes, you must synchronize them in a separate step.
3 Command Differences This chapter describes the differences between LVM and VxVM commands, and tasks. It includes a task comparison chart which lists some of the tasks performed using LVM with a near equivalent task performed using VxVM. It also provides a list of VxVM tasks which are not available with LVM, and the LVM features currently not supported in VxVM.
Command Differences LVM and VxVM Command Equivalents LVM and VxVM Command Equivalents The table below lists the LVM commands and a near equivalent command to use in VxVM. For more information, refer to the Task Comparison chart. For information on VxVM commands, refer to the VERITAS Volume Manager documentation package (see the Preface). Table 3-1 LVM lvchange Command Comparison Description/Action Changes the characteristics of logical volumes.
Command Differences LVM and VxVM Command Equivalents Table 3-1 LVM lvextend Command Comparison (Continued) Description/Action Increases disk space allocated to a logical volume. VxVM Description/Action vxassist Increases a volume in size with the growto or growby parameter. Example: vxassist growto vol_name 200M, vxassist growby vol_name 100M vxassist creates and modifies volumes. lvreduce Decreases disk space allocated to a logical volume.
Command Differences LVM and VxVM Command Equivalents Table 3-1 LVM lvsplit Command Comparison (Continued) Description/Action Splits a mirrored logical volume into two logical volumes. VxVM vxassist snapshot Description/Action The snapshot operation takes one of the attached temporary mirrors and creates a new volume with the temporary mirror as its one plex. Example: vxassist snapshot vol_name new_volume lvmerge Reverses and converts the lvsplit logical volumes to a single logical volume.
Command Differences LVM and VxVM Command Equivalents Table 3-1 LVM pvcreate Command Comparison (Continued) Description/Action Makes a disk an LVM disk. VxVM vxdisksetu p Description/Action Brings a disk under VxVM control. Example: vxdisksetup c0t3d0 Option 1 in the vxdiskadm menu adds or initializes one or more disks. pvdisplay pvchange Chapter 3 Displays information about physical volumes in a volume group.
Command Differences LVM and VxVM Command Equivalents Table 3-1 LVM pvmove Command Comparison (Continued) Description/Action Moves allocated physical extents from source to destination within a volume group. VxVM Description/Action vxevac Moves volumes off a disk. vxsd mv Performs volume operations on a subdisk. Moves the contents of old subdisk onto the new subdisks and replaces old sub disk with the new subdisks for any associations.
Command Differences LVM and VxVM Command Equivalents Table 3-1 Command Comparison (Continued) LVM Description/Action vgchange Activates or deactivates one or more volume groups. vxdg -g diskgroup set activatio n= mode Activates a shared disk group. vgextend Extends a volume group by adding one or more disks to it. vxdiskadd Adds a disk to the disk group. vxdiskadm Option 1 in the vxdiskadm menu adds disks to the disk group. Reduces a volume group by removing one or more disks from it.
Command Differences LVM and VxVM Command Equivalents Table 3-1 LVM Command Comparison (Continued) Description/Action VxVM Description/Action vgsync Synchronizes mirrors that are stale in one or more logical volumes. vxrecover Starts resynchronization and recovery of volumes. vgremove Removes the definition of a volume group from the system. vxdg deport Deports a disk group from the system. vxdiskadm Option 9 in the vxdiskadm menu removes a disk group. Removes a volume group from the system.
Command Differences Comparison of LVM and VxVM Tasks Comparison of LVM and VxVM Tasks This section contains a list of tasks that you can perform using LVM, and near equivalent tasks which you can perform using the VERITAS Volume Manager. You can perform the LVM tasks by using SAM or the command line interface. Similarly, you can choose to perform VxVM tasks by using the VERITAS Volume Manager Storage Administrator or from the command line interface. This document focuses on the command line interface.
Command Differences Comparison of LVM and VxVM Tasks Table 3-2 Task Type VxVM LVM and VxVM Task Comparison (Continued) Description Example Bring a disk under Volume Manager control. vxdiskadd device_name LVM Create a volume group vgcreate /dev/vol_grp /dev/dsk/disk_name VxVM Create a disk group. vxdg init disk_group disk_name Option 1 in the vxdiskadm menu adds a disk and initializes it. Option 1 in the vxdiskadm menu performs this task. LVM Add a new disk to the existing volume group.
Command Differences Comparison of LVM and VxVM Tasks Table 3-2 Task Type LVM VxVM LVM and VxVM Task Comparison (Continued) Description Example Extend a logical volume or increase space allocated to a logical volume. lvextend -l 50 /dev/vol_grp/lvol_name Increase the volume by or to a given length.
Command Differences Comparison of LVM and VxVM Tasks Table 3-2 Task Type LVM LVM and VxVM Task Comparison (Continued) Description Example Export and deactivate an LVM volume group, and its associated logical volumes. vgchange -a n vol_group Deport a disk group to disable access to the specified disk group. A disk group cannot be deported if any volumes in the disk group are currently open. vxdg deport disk_group LVM Back up volume group configuration information.
Command Differences Comparison of LVM and VxVM Tasks Table 3-2 Task Type VxVM LVM and VxVM Task Comparison (Continued) Description Destroy a disk group. Example vxdg deport disk_group vxdg init disk_group LVM Extend a volume group by adding LVM disks to the volume group. vgextend /dev/vol_grp/\ /dev/dsk/disk_name VxVM Add one or more disks to the disk group.
Command Differences Comparison of LVM and VxVM Tasks Table 3-2 Task Type LVM LVM and VxVM Task Comparison (Continued) Description Mirroring an LVM root disk involves several steps. Example pvcreate -B /dev/rdsk/second_disk mkboot -l /dev/dsk/second_disk vgextend /dev/vol_grp \ /dev/dsk/second_disk lvextend -m no_of_mirrors \ /dev/vol_grp/root_lvol \ /dev/dsk/second_disk lvlnboot -r /dev/vol_grp/lvol_name VxVM Mirroring the VxVM root disk.
Command Differences Comparison of LVM and VxVM Tasks Table 3-2 Task Type LVM and VxVM Task Comparison (Continued) Description Example LVM Display information about volume groups. vgdisplay -v /dev/vol_grp VxVM Display disk group information. vxdisk list vxprint -g disk_group vxdg list Display information about a specific disk group. vxdisk list disk_group LVM Display information about physical volumes. pvdisplay /dev/dsk/disk_name VxVM Display information about Volume Manager volumes.
Command Differences Comparison of LVM and VxVM Tasks Table 3-2 Task Type LVM and VxVM Task Comparison (Continued) Description Example VxVM Deport a disk group. You must unmount and stop any volumes in the disk group first. vxdg deport disk_group LVM Set up alternate links to a physical volume. vgcreate /dev/vol_grp\ /dev/dsk/disk_name /dev/dsk/disk_name_2 If a disk has two controllers, you can make one primary and the other an alternate link.
Command Differences Comparison of LVM and VxVM Tasks Table 3-2 Task Type VxVM LVM and VxVM Task Comparison (Continued) Description Example Remove mirrors or reduce the number of plexes/mirrors. vxplex -o rm dis plex_name Remove a volume with the plexes associated with it. vxedit -rf rm vol_name LVM Increase the number of mirror copies. lvextend -m 2 /dev/vol_grp/lvol_name VxVM Add mirrors to a volume or increase the number of plexes.
Command Differences Comparison of LVM and VxVM Tasks Table 3-2 Task Type LVM and VxVM Task Comparison (Continued) Description Example VxVM Resynchronize operations for the given volumes. vxvol resync LVM Synchronize extents within mirrored logical volumes in a volume group. vgsync /dev/vol_grp VxVM Resynchronize operations for the named volumes, or for volumes residing on the named disks.
Command Differences Tasks With No Direct LVM Equivalents Tasks With No Direct LVM Equivalents The following table lists tasks which have no direct LVM equivalent. Most of these tasks can be performed either with the VERITAS Enterprise Administrator (VEA) GUI, or the command line interface. For more information, refer to the VERITAS Enterprise Administrator (VEA 500 Series) Getting Started guide and the VERITAS Volume Manager Administrator’s Guide.
Command Differences Tasks With No Direct LVM Equivalents Table 3-3 Additional VxVM Tasks with no LVM equivalents (Continued) Task Description Example Recover volumes on a disk. vxrecover -g disk_group vol_name medianame Display a DMP node. vxdisk list meta_device Rename a disk group. vxdg -tC -n newdg_name Rename a volume. vxedit -v rename name newname Update the /usr/fstab file with the new name. Add a DRL log to a volume. vxassist addlog vol_name Create a snapshot copy of a volume.
Command Differences Existing Features in LVM not supported in VxVM Existing Features in LVM not supported in VxVM Some of the existing features in LVM are not supported in the current release of VxVM. Given below is a table with the unsupported LVM features, and possible workarounds in VxVM. Table 3-4 LVM features and VxVM equivalents LVM Feature VxVM Equivalent Physical volume groups VxVM has no equivalent feature.
Command Differences Existing Features in LVM not supported in VxVM 70 Chapter 3
4 SAM and the VEA This chapter describes the VERITAS Enterprise Administrator (VEA) graphical user interface (GUI), and its relationship with the LVM GUI, and the System Administration Manager (SAM). The following topics are discussed in this chapter: • “Listing Disk Devices in SAM” • “Listing Logical Volumes in SAM” SAM and the VEA coexist as independent entities. The VEA recognizes and labels LVM volumes and disks, but does not manage them.
SAM and the VEA Listing Disk Devices in SAM Listing Disk Devices in SAM To list disk devices in SAM, from the Disks and File Systems SAM area, select Disk Devices. The Disk Devices screen lists the system’s disk devices. When VxVM is installed on the system, SAM includes a “Use” column to indicate whether a disk is under LVM or VxVM control, or whether it is unused. If a VxVM disk is online and part of a disk group, the disk group name is listed under the “Volume Group” column.
SAM and the VEA Listing Disk Devices in SAM Figure 4-1 Displaying Disk Devices Using SAM Listing Volume Groups and Disk Groups in SAM To list volume groups and disk groups in SAM, from the Disks and File Systems SAM area, select Volume Groups. The Volume Groups screen lists the LVM volume groups and the VxVM disk groups on the system. The following figure shows a Volume Groups screen for the same example system.
SAM and the VEA Listing Disk Devices in SAM Figure 4-2 74 Listing LVM Volume Groups and VxVM Disk Groups with SAM Chapter 4
SAM and the VEA Listing Logical Volumes in SAM Listing Logical Volumes in SAM To list logical volumes in SAM, from the Disks and File Systems SAM area, select Logical Volumes. The Logical Volumes screen lists the LVM logical volumes and the VxVM volumes on the system. The “Type” column indicates whether a volume is controlled by LVM or VxVM. The “Use” column shows whether a volume is in use and if so, what it is used for. The following figure shows a Logical Volumes screen for the same example system.
SAM and the VEA Listing Logical Volumes in SAM Figure 4-3 76 Listing LVM Logical Volumes and VxVM Volumes with SAM Chapter 4
A Conversion Error Messages This appendix lists the error messages that you may encounter when conversting LVM volume groups to VxVM disk groups and volumes. For each error message, a description is provided of the problem, and the action that you can take to troubleshoot it.
Conversion Error Messages Analysis shows that there is insufficient private space available to convert this volume group Analysis shows that there is insufficient private space available to convert this volume group • Description The error message indicates the maximum amount of records that can be stored in the private space, and how many records are needed to convert this particular volume group.
Conversion Error Messages The conversion process was unable to deactivate the volume group vol_grp_name d. Create a dummy link to the raw device, for example: # ln /dev/rdsk/c0t0d0 /dev/rdsk/temp e. Destroy the LVM headers using pvcreate -f on the dummy link, for example: # pvcreate -f /dev/rdsk/temp f. Remove the dummy link to the raw device, for example: # rm /dev/rdsk/temp g. Restore the headers from the lvmconf backup, for example: # vgcfgrestore -n /dev/vg01 /dev/rdsk/c0t0d0 h.
Conversion Error Messages Too many LVM Volumes to convert in this LVM Volume Group Install the required license before attempting the conversion. Too many LVM Volumes to convert in this LVM Volume Group • Description If there is insufficient private space, the conversion is not allowed to continue. Also, the conversion records already generated are removed such that in the event of an unexpected crash and reboot, the conversion cannot proceed automatically.
Conversion Error Messages vxdiskadm or vxvmconvert is already being run and these programs cannot run concurrently vxdiskadm or vxvmconvert is already being run and these programs cannot run concurrently • Description The system detects that the vxdiskadd or vxvmconvert program is already running. • Action Retry at a later time. Otherwise, if you are certain that no other users are running either of these programs, remove the file .DISKADD.
Conversion Error Messages vxdiskadm or vxvmconvert is already being run and these programs cannot run concurrently 82 Appendix A
Glossary block A unit of space for data on a disk, typically having a size of 1024-bytes. Dirty Region Logging Dirty Region Logging (DRL) is an optional property of a volume, used to provide a speedy recovery of mirrored volumes after a system failure. DRL keeps track of the regions that have changed due to I/O writes to a mirrored volume. file system The organization of files on storage devices.
Glossary set of continuous physical extents [PEs] set of continuous physical extents [PEs] Set of physical sectors (blocks) contained within a single physical volume. A physical extent is a specific, contiguous region of the disk where data resides. This is of a constant size usually of 4 MB and has no partitions. VGRA The Volume Group Reserved Area (VGRA) is a region on an LVM disk that holds LVM configuration information and is at a fixed location.
